Post-consumer recycling of Tetra Pak?: Starting a "new life" as filler in sustainable polyurethane foams

Tetra Pak (R) is a laminated packaging consisting in cardboard, aluminum and LDPE layers, used to preserve several food products and beverages. Recycling of such material is not trivial; usually packages end up in the landfill. In this study, Tetra Pak (R) scraps were used as reinforcing filler for sustainable composite polyurethane (PU) foams, without components separation. Foams were prepared through polyaddition reaction between di-isocyanate source and biobased polyols, in presence of suitable additives and blowing agents, and by loading Tetra Pak (R) at 5 wt% and 20 wt%, respectively. The effect of filler size, shape and concentration on thermal, morphological and mechanical characteristics of the foams was investigated. The intercalation of Tetra Pak (R) corresponded to compressive stress (3 times more) and the flexural stress (50% more) increases with respect to the unloaded foam. The so-obtained foams can be used in food packaging (as containers) and in other applications.